Telephone system



Sept. 2, 1924. 1,507,144

F. F. VALLETTE TELEPHONE SYSTEM Filed Dec. 1, 1922 /n venfor: Frederic f. Val/e776 Patented Sept. 2, 1924.

UNITED STATES PATENT OFFICE.

FREDERIC F. VALLETTE, OF BERWYN, ILLINOIS, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE SYSTEM.

Application filed December 1, 1922.

To all whom it may concern:

Be it known that I, Fnnnnnro F. VALLETTE, a citizen of the United States, residing at Berwyn, in the county of Cook, State of Illinois, have invented certain new and useful Improvements in Telephone Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone systems and more particularly to systems wherein connections are established without the intervention of operators.-

In many of the present day business activities, and particularly in connection with the business of a broker, it isoften desirous, and in many cases necessary, that one member of a firm be able to get in touch with another member of the firm substantially instantaneously, in order to advise him of the sale of stocks and the like. In such cases where time is a most important element in the successful transaction of business, a system of communication is desirable wherein the time consumed in establishing a telephonic connection by an intermediate operator is used to actual advantage by the calling party.

It is anobject of this invent-ion, therefore, to improve a system for establishing telephonic connections without the intervention of operators. y

Another object of this invention is to signal the called station on a private line by automatic machine ringing under the control of the calling station.

The foregoing and other objects of this invention are obtained by the provision of a private 'line interconnecting two subscribers sets and having in either end thereof a relay responsive to the removal of the receiver from the switchhook at the station on that end to operate other electromagnetic devices whereby a source of machine ringing current is automatically connected to the called line.

The invention will be readily understood from the following description, and by reference to the accompanying drawing which shows two subscribers sets and a private line circuit interconnecting said sets.

.Let. it be assumed that'the subscriber at station A desires to communicate with the part-y at station, B. The subscriber at station A in removing the receiver from the switchhook establishes an energizing circuit for supervisory relay .10, which may be Serial No. 604,200.

traced from grounded battery, through the left-hand winding of repeating coil 11, conductor 12, winding of relay 10, lower armature and back contact of relay 13, over the subscribers line loop including the apparatus at station A, the upper armature and back contact of relay 13, conductor 14, and thence to ground through the upper lefthand winding of repeating coil 11. Relay 10 energizes in this circuit and establishes a circuit for relay 15, extending from grounded battery through the winding of relay 15, conductor 16 and thence to ground through the armature and front contact of relay 10. Relay 15 upon energizing prevents, at its left-hand armature, the operation of relay 13 at this time. At its right-hand armature, relay 15 establishes an energizing circuit for relay 18 which may be traced from grounded battery through the winding of relay 18, conductor 19, right-hand armature and back contact of relay 20, conductor 21, conductor 32, armature and back contact of relay 22, conductor 23, armature and back contact of relay 24L, conductors 26, 28 and 27 and thence to ground through the right-hand armature and the front contact of relay 15. It is to be noted that relay 22 is shunted by a portion of the circuihjust traced including the armatures of relays 22 and 24 and the conductor 23. This shunt is necessary at this time in order to prevent relay 22 from operating and thereby shunting out relay 18 before the machine ringing source 17 has been connected to the calledpartys line. Relay 18 in operating in the'circuit previously traced places ground on the tipconductor of the called line and connects at its lower armature and front contact, the machine ringing source 17 to the ring conductor of the called line. The ringing current flows from the ringing source 17 through the winding of marginal relay 2 f, conductor 25, lower armature and frontcontact of relay 18, and thence over the subscribers line loop including the apparatus at station 13, to ground at the upper armature and front contact of realy 18 to actuate the bell at station B.

Upon noting the signal, the subscriber at station 13 removes the receiver from the switchhook thereby bridging the line conductors and reducing. the resistance of the line to such an extent as to permit the marginal relay 24: to operate. Relay 24 in operating removes the shunt provided the ring conductor leading to station B.

Relay 24 also deenergizesupon the release of relay 18. Relay 18 is made slow releasingin order that the charge caused by the effect of the ringing current on the normal capacity of the line may be dissipated before the line is thrown back on the repeat ing coil 11 to prevent the calling subscriber atstation A from receiving the effect of the charge.

lVhenrelay 18 dcenergizes a circuit is established for supervisory relay 29 which may be traced from grounded battery through the upper through the lower right-hand winding of repeating coil 11, conductor 30, winding of relay 29 back contact, and lower armature of relay 18 over the line loop of station B, the upper armature and back contact of relay 18, conductor 31, and thenceto ground right-hand winding of repeating ,coil' ll, Supervisory relay 29 energizes in the circuit just traced, and establishes a circuit for relay 20 which may be traced from grounded battery, through the winding of relay 20, conductor 33, to ground th ough the front con -ac a d a ature of relay 2.9 At its left-hand armature and front contact relay 20', on energizing, connects an additional ground to the circuit including the winding of relay 22 thereby prevent ng this relay r m r leasing be lfore relay 20 releases. The subscribers at stations A and B a n w in telephonic c nnection with one another and may proceed toscarry o a conversation.

Upon completion of the conversation the subscriber at station A'replaces the receiver on the switchhook thereby interrupting the energizing circuit for relay 10. 'Relaylo r l a es i ar ature hereby int rupting the circuit for relay 15. Relay 22 is st ll held operated under the control' of relay 20,

in a circuit extending from groundedbattery through the armature, front contactand winding of relay 22, conductor 28, conductor L0, and thence to ground through the armature and front contact of relay 20. The

ubsc iber a station E upon eplacing the receiver on the switchhook interrupts the energizing circuit for supervisory relay 29 which retracts its armature and opens the circuit for relay 20. Relay 29in retracting its left-hand armature interrupts the circuit forrelay 22 which relay thereupon deenergizes returning the circnit to normal 1 His to e note that during theiriij gi g period, the line of the called subscribefis 5 6i removed from the repeating coil 11, the repeating coil itself not being employed in the ringing operation.

From the foregoing description, it is obvi one that either subscriber by the mere act of removing the receiver from the switchhook can automatically signal the other subscriber and be telephonically connected therewith. i

What'is claimed is: I I

1. In a telephone system, a line comprising inductively coupled sections, a substation normally "connected to each of said sections, a source of ringing, current, a relay responsive to the removalof the receiver at either of said stations for disconnecting the other station from its corresponding line section and connecting said cur-rent source to said other station, a normally shunted relay common to said stations, and means responsive to the removal of the receiver at said other station for removing the shunt from said normally shunted relay whereby said first mentioned relay is restored, disconnecting said ringing current from said other station and reconnecting said other station to its corresponding line section. a

2, In a telephone system, a line compris ing inductively coupled sections, asubstation normally connected to each of said sec tions, a source of ringing current, a' relay responsive to the removal of the receiver at either of said stations for disconnecting the other station from its corresponding line section and connecting I said current source to said other station, a normally shunted relay common to said stations, and a marginal relay controlled from said other station for removing the shunt from said normally shunted relay whereby said first mentioned relay is restored, disconnecting said ringing current from said other station and reconnecting said other station to its corresponding line section.

3; In a telephone system, a line comprising inductively coupled sections, a substation-normally connected to each of said sections, a source of ringing current, a relay responsive to the remo'valof thereceiver at either of said stations for disconnecting the other station from its corresponding line section and connecting saidvcurrent source to sa d oth r st on, a marg n r lay resplo sive to'fihe re lOVaI of the receiver at said other station, and means controlled by said marginal any t r c nnec ng s id stat its corr p d ng line, se on an removing said urr nt some from c n ction therewith.

4. In a telephone system, a air of stations, a link circuit interconnectlng said stations, a source of signaling current, means controlled from either of said stations for automatically connecting said Source of current to the other of said stations, a marginal relay common to said stations, and circuit connections arranged so that said marginal relay may be controlled from either of said stations to automatically disconnect said source of current in response to the answering of the called station.

5. In a telephone system, a link circuit, a subscribers station at each end of said link circuit, a source of ringing current, means controlled from either of said stations for connecting said source to the opposite station to signal said opposite station, means operative in response to the answering of the opposite station to automatically disconnect said source of ringing current, and a relay for each end of said link circuit for rendering the conductors of said link circuit discontinuous during the signaling interval.

In Witness whereof, I hereunto subscribe my name this third day of November A. D., 1922.

FREDERIC F. VALLETTE, 

